The present invention relates to a wafer-tumbler lock, and more particularly to a rekeyable wafer-tumbler lock with facially engageable wafer tumblers.
Most common locks are pin-tumbler cylinder locks or wafer tumbler cylinder locks. Each of these locks contains a cylinder or plug which rotates within a housing or shell. In the pin-tumbler locks, pin holes containing top and bottom pin tumblers extend transversely through both the cylinder and the housing crossing a shear line, which is the boundary between the cylinder and the housing. The pin tumblers slide up and down within the pin holes defining a locked position and an unlocked position. When a pin tumbler crosses the shear line, the pin tumbler interferes with the rotation of the cylinder and the cylinder remains locked. When the correct key is inserted in the lock, the biting on the key contacts the pin tumblers and locates the pins within their pin holes such that no pin crosses the shear line. The cylinder can then rotate within the housing when a torque is applied by the key to unlock the lock.
Wafer-tumbler locks have wafer-shaped tumblers which slide up and down within channels that extend from the cylinder to the housing. The wafer tumblers are spring loaded so that they can extend out of the cylinder and into a locking slot within the housing, to prevent rotation of the cylinder relative to the housing in a locked condition. The center of each of the wafer tumblers has an opening for receiving a key. The correct key moves the wafer tumblers out of the locking slot, such that torque applied to the cylinder rotates the cylinder within the housing and unlocks of the lock.
To avoid or reduce the costs of re-keying locks, several types of re-keyable locks that do not require disassembly have been developed for pin-tumbler locks. However, uncomplicated and cost effective re-keyable locks for wafer tumbler systems are still relatively uncommon.
Accordingly, it is desirable to provide an inexpensive re-keyable wafer-tumbler lock assembly.